


Cup Runneth Over

by Belmont



Category: Fate/Grand Order
Genre: Alternate Universe - Canon Divergence, Body Horror, Gore, Implied Sexual Content, M/M, Unhealthy Relationships
Language: English
Status: Completed
Published: 2020-04-02
Updated: 2020-04-02
Packaged: 2021-03-01 01:09:00
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 2
Words: 2,845
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23446792
Author URL: https://archiveofourown.org/users/Belmont/pseuds/Belmont
Summary: I wasn't worried before I was born, why would I worry after I'm gone?
Relationships: Fujimaru Ritsuka/Angra Mainyu | Avenger
Kudos: 25





	1. Cup Runneth Over

**Author's Note:**

> This was originally drabbled for someone on twitter and I extended it out into a minific because I quite like Angry Mango. He's exceptionally hard to obtain in FGO, which makes him that much more intriguing to me.
> 
> This version of him is a bit different from the in-game version, which should be apparent from the dialogue. Both characters are physically around mid-twenties, but obviously Angra is much, much older conceptually. In this version, he's also not directly related to Shiro Emiya, and tends to take up forms of his 'previous masters'. 
> 
> Applicable warnings: graphic gore, body horror, grail-related hallucinations, semi-graphic implied sexual content between two male characters. Also, 'Mash' is 'Mashu' in this, which might trigger someone so I have to mention that here LOL. 
> 
> Description is lyrics from Black Static by HEALTH, which you may want to listen to while reading for ambiance.

The shadow of Emiya moved across the warping floor like a sluggish phantom.  
  
Ritsuka’s eyes watered, trying to adjust to the change in saturation and flood of light as the world around him grew distorted. He’d lost to the great caster, Solomon, and he could only watch as the very fibres of Mashu’s body dissolved before him into a pillar of ash. Totally helpless, the greater grail slipped freely out of his hands within seconds.  
  
He’d failed his mission, which was the last memory he had.  
  
Emiya’s body slowed, standing above him with an odd quiver to his outline. A shape changing and moving, tricking his eyes as the sky bled into the rising mountains of black, inky viscera behind the servant which he’d never summoned.  
  
The shapes crept across Emiya’s limbs, across his features which were too soft to belong to the fabled assassin- eyes that were wrongly colored and mismatched- a blood red bolt of cloth loosely tied around unkempt pitch black hair.  
  
“Hello,” That voice didn’t belong to anyone in particular, but simultaneously belonged to everyone he’d ever met. “I’m here to offer you a deal.”  
  
Ritsuka exhaled, or he thought he did, but his body felt terribly far away.  
  
“I need you,” The man who was not Emiya smiled- it was a gentle, peaceful look. His gaze was full of humility, soft lips pursed like he was expecting the brunette to suddenly speak over him. Unrealistic in this state, but perhaps it was out of pity.  
  
Or, he was being taunted while helpless. Ritsuka’s hands twitched upwards, and his fingers coiled around one of the figure’s narrow ankles. The hold was limp, but the man didn’t express any discomfort or agitation at the touch.  
  
“You want me to help you, and I will,” The lines blended forward, with the unidentifiable face abruptly appearing inches away from his own. A dark shape filled the space behind the figure until the silhouette of another person stood behind him, or maybe not, because the darkness of what he thought was limbs branched forward into long malformed tree branches. The tendrils spiraled into oblivion, like dirty water flowing down a reddened drain.  
  
“-tell me that you need me.” The black of his right iris swelled, while the bright gold of his left iris narrowed into a pinprick of light. “You will get your wish, if you tell me that you need me.”  
  
Ritsuka’s chest rose and fell quickly, mouth opening. Nothing could come out of him, even if he tried forcing the words into existence.  
  
So, he thought them. _Yes, I need you. Save me, please. My job is unfinished.  
  
_Strange laughter bubbled into the air around him, lingering there until the mysterious figure sharply inhaled. “What was your job?”  
  
_To save humanity._ Ritsuka winced, realizing how utterly absurd that must seem. _My task was to save humanity from evil.  
  
_“What a noble duty.” That gentle expression loomed dangerously close, and the brunette tilted his head to follow the face. His apparent savior, whom was nameless and formless and may perhaps be a last ditch effort from his brain to assuage him in the final throes of life, was so close to him now that he could feel breath against his lips.  
  
“Pity that duty was bestowed upon someone like you.”  
  
His desperate touch dropped away from the ankle the moment a mouth sealed over his own. Lips forced apart by an invading tongue, the slippery muscle tasted him shamelessly down to the backs of his molars. A foul, coppery tang flooded in with his saliva, and his held breath suddenly returned to his lungs through a deep heave once the stranger parted from him.  
  
“You will give me what you have, in exchange for your wish.” The man was crouched alongside his left, body resting comfortably against Ritsuka’s gutted torso. “I will give you your life back, and I will give you a chance to fulfill your duty.”  
  
_I have nothing._ His partner’s evisceration at the hands of Solomon was all that came to mind, and Mashu’s power wasn’t his to pass along to anybody.  
  
“You have everything. The light of the world borne from you, it will be mine.” That soft mouth returned, nibbling his bottom lip gently before a tongue traced the swell of it corner to corner. A hand rested on one of his exposed ribs, smoothing along the bone until the dark skin met pulped pale flesh.  
  
Only then did the stranger’s smile become a subtle scowl. Ritsuka couldn’t be bothered with any fear, mind ruminating on the feeling of being kissed by this otherworldly thing. The _only_ feeling, which surely would precede the breath of life he was promised. His second chance, where was it?  
  
“I am all the evil of your world, both above and below you.” The slender bone cracked easily inward with a swift flick of his wrist, and the stranger leaned close to the body’s sternum without breaking the eye-contact he’d made with his newfound ‘master’.  
  
“You have called out to me, and I have answered. Whatever follows you now, know that you brought it unto yourself. Know too, that in the end of your life, you will have _gained_ nothing. You will _be_ nothing. All you are, and all you have, will be mine.”  
  
The rib was torn upwards and out of the body, held against the myriad of cryptic markings spiraling from Angra Mainyu’s heart. The brunette felt no pain, nor did he suffer, even as his corpse began to fill with the black, tarlike swill of the corrupted holy grail- the cup that had shattered in the hands of Solomon, and the same cup that had been collected piece-by-piece by the shadow of the world’s unforgiving contempt.   
  
“I will see you soon, master. Until then.”  
  
-  
  
When he awoke again, the blue, cloudless sky shone brilliantly through softly rustling leaves of the tree he’d been propped against. Mashu’s head was eclipsing the sun conveniently before him, peering down with a childlike inquisitiveness. It was as if all his suffering was completely washed away. She was safe, in one piece.  
  
“Senpai?”   
  
Ritsuka, cradling his aching chest, could only smile.  
  
-  
  
Time had rewound itself, months before he’d dared take on David’s corrupted son. His chance to fight the end-all battle was renewed, and his servants seemed more dedicated than ever in light of their master’s sudden vigor.  
  
At night, it became apparent that the vigor was not without a steep cost.  
  
Darkness streamed into the cracks beneath his door, through the blinds of his window, from the seam between the ceiling and the very walls around him. It crept slowly and sweetly forward without fail, the ichor pooling at his feet in wait for his inevitable acknowledgement.  
  
Tattooed hands danced up his thighs then, lips pressed against the front of his boxers, and the warmth of a needy body rocked lazily against his calves.  
  
Angra came at a strange price.  
  
Not only had he given the conceptual servant his whole spirit, but he was expected to continually provide him with a steady source of mana. Evil sought slaughter, and derived energy from untimely death, but Ritsuka suspected there was a certain sick delight he drew from siphoning all of the master’s mana into his personal pool- depriving all other servants from accessing the nectar, and forcing them to find other means to power on even as the demands for their performance grew steeper still.   
  
Torture, really.  
  
As the nights passed, his apprehension toward the act of mana transfer whittled into nothing. That odd ghostly shape assumed the same form, a young man with darkly stained skin and mismatched eyes, to which Ritsuka had willingly forfeit everything to. He allowed himself to be used freely, at the whims of the mysterious being, and upon waking it was as if the sun dissipated any trace of Angra from the room or from his body.  
  
Tonight was no different. His fingers pulled at the red fabric wrapped loosely around his partner’s forehead until it fell away, exposing the lidded gaze of the stranger to the dim light of the room. Ritsuka’s erection rested against a tattooed cheek, lips pressing softly against the engorged shaft- he’d been interrupted in the midst of his ritual ministrations, but seemed expectant.  
  
“When will you be satisfied?” The master’s voice was small, holding the sort of exhaustion akin to an overworked soldier.  
  
Gold and obsidian dilated, though the irises vanished beneath thick lashes. “I will never be satisfied. I am always satisfied. You know that I want for nothing.”  
  
“You told me you wanted the light in this world.”  
  
Angra Mainyu reached for the divot in Ritsuka’s bare chest- the subtle indentation of a missing rib- a piece he’d claimed as a reminder of their binding. Such a piece was a bargaining chip, which had long sunken into the filthy sludge of the corrupted grail and dissolved in the acrid poison of the world’s hatred.  
  
“Each passing day, I take a little more.” Warm fingers of his opposite hand brushed over the brunette’s perineum, feeling the tight ring of flesh just past that twitch upon his touch. “ _You_ will die, as all things die, and you will fade as all things do once your battle is done.”  
  
The fingers against his opening vanished, and the tattooed man rose from the floor without removing his other hand from the indent of the missing rib. “But the light I’ve taken from you will remain thereafter. This alone will sustain me.”  
  
His body involuntarily shivered, as if what was left of his soul was trying to escape from the imminent demise standing calmly between his legs. Angra lazily cupped one of Ritsuka’s pectorals after finally parting from the other’s missing rib, and the carefree smile once again painted those deceptively soft features.  
  
“You agreed to this, did you not?”  
  
-  
  
Well into the night, shadows moved along the walls in formless splashes of black and crimson.  
  
The room was quiet outside of the occasional muffled cry or hard breath. Though imposing in his appearance, the stranger was of a lithe build. Ritsuka could fold him at the waist with ease, both legs limp over his shoulders while the brunette’s hips moved automatically. It seemed that penetration alone was always enough for the servant, who yielded eagerly until his master reached climax. There was no particular chase for desire, nor greed toward his own pleasure in his actions. His body, like the bottomless grail, hungrily swallowed the magical energy until the summoner collapsed against him from exhaustion.   
  
Inky darkness coated half of his room, creeping closer. Ritsuka pretended not to see this, face buried in the cryptic markings burned across the stranger’s collarbone. The evil seeped over the edge of the bed, but spared their bodies from being swallowed up into the nothingness.  
  
Perhaps because he’d already been claimed by the primary vehicle of such miasma.  
  
Arms closed around him, tattoos blending together and running freely off their owner until Angra’s skin was indistinguishable from the patterns that blanketed his own, and he allowed himself to be dragged away from the disturbing reality of his choices into a dreamless slumber.  
  
-  
  
When he failed to win the battle against the grand caster a _second_ time, Ritsuka wasn’t devastated. He felt nothing but a strange sense of understanding; this time, his failure was preordained. Funneling so much of himself into the weakest servant wouldn’t result in a victory. It was a death sentence.  
  
“I will do as you wished.” Voices chided softly, smoothing along his shoulders and righting his skewed uniform back into place. “Watch, though please, don’t be disappointed.”  
  
Solomon’s miserable face watered, swelled, jaw cracking forward with the sheer force of whatever darkness was evacuating itself suddenly from his body. His arms sloughed off, torso collapsing inward with resounding bellows of pain- or perhaps frustration. Skeletal remains- what could be a vestigial Goetia- struggling vainly against some unseen force which Ritsuka could only assume was the ichor- having been embedded within the villain, though clearly it served a new master.  
  
Or, it hadn’t served anything at all. It was simply moving on to the next victim.  
  
“Yes,” Angra’s breath was warm against his neck. “You understand now, where your light has gone.”  
  
He could see the remains surge forward, bubbling with an intense steaming heat; from them, a fragment of silvery pulp lurched upward and into the air above the desecrated king. To the human’s eyes, this resembled liquid mercury, but there was something wholly sinister about the wavelike ripple to the center. His servant’s soothing presence was abruptly torn away, and without his volition, his body acted to run from the mysterious shape.  
  
Before he could turn, it consumed him.  
  
Nothing remained after.  
  
As though no calamity had occurred, the landscape of the city seemed serene and untouched by disaster. Mashu, too, had been spared. Her body was draped weakly over the back of her shield, though she stirred subtly as if on the cusp of waking. Perhaps out of luck, or perhaps due to Galahad’s will, the servant was allowed to exist freely on even without her master.  
  
Not too far from her, lodged into the bark of a tall tree, was what looked at first glance to be a branch stripped bare- though closer inspection would reveal that it was a long fragment of bone; a rib, bearing strange symbols that swirled and glided over the ivory like lazy shadows.  
  
The evil of the world would be called upon again in time, though his appearance would be that of a young man with sharp features, unfriendly eyes, and an odd indentation in the flesh of his chest. 


	2. Omake / Valentine

**Summary for the Chapter:**

> A little bonus, based on the valentines events in Fate: Grand Order.

“Chocolate?” Mismatched gaze squinted dubiously, but there was an unmistakable grin on the spirit’s face. “I can have this? You’re quite sure?”  
  
Ritsuka’s brow furrowed, and he nodded sheepishly. “I bought it for you, I mean, I thought you might like something sweet. I don’t know, is that strange?”  
  
“No, I like it, I do. I’m going to eat it right now, in fact.” His fingers scrabbled at the foil wrapping until the corner of the bar revealed itself, to which he bit into the sweet milk chocolate with obvious adoration. “Mmm, it’s good! Humans make waste of such nutrients, but the taste really is delicious.” Blue eyes tried not to follow the little pink tongue darting out to lick his lips, but Ritsuka’s cheeks darkened from shameful thought regardless.  
  
“You know, I have nothing I can give you in return.” Angra blinked at the bar, taking another bite of the opposite corner. “I own nothing, and I can gain nothing. Even if I fight for you, I won’t be strong enough to win any battles for you.”  
  
“I don’t want anything in return, I just wanted to give you something… the act itself makes me feel good.”  
  
Instantly, the stranger’s expression darkened as a cruel smile crossed his lips. “ _Huh_? You gave me something out of selfish desire. You expected the kind of answer like: ‘Ah, master, I have nothing to give you in return, so I’ll give you my _body_.’ This is what you were expecting, or, nothing at all. I know you, I know all humans are just like you.”  


A single bead of sweat found its way down Ritsuka’s temple, his face twitched, but he couldn’t figure out what sort of expression to be making. Shock, no, maybe disdain. Had he really been so transparent? Was it because of the bond they shared? All of the hours sunk into training this seemingly hopeless servant, based on a wild dreamlike promise.  
  
“Hah! Your face became strange all of a sudden. Forgive me, won’t you? Your heart isn’t so mysterious, but it’s nothing to be ashamed of.” Then, the cruelty softened into a warm look of unbridled affection. “I like you because you think you’re very good at pretending.”  
  
Another bite of chocolate, and the tattooed servant held up his finger. “Mhm, actually, I can give you something. It’s nothing you don’t have already, and nothing you wanted, but it’s something. Good enough, right?”  
  
The bar was held between off-white teeth, both hands digging into the loosely tied red sash keeping Angra Mainyu modest. From the bottom of the article, a long strip of the fabric was torn free and held outward.  
  
“Hold out your arm, either arm.” Ritsuka obeyed, feeling the bolt of red cloth be secured in place around his right bicep with a tight knot. “There, now you have something in exchange. It’s a bit stained, but it’s still vibrant.”  
  
The dirty bit of cloth now tied to his arm had him raising his eyebrows, though he smiled despite himself. “Thank you.”  
  
“You’re welcome, for sure. The others will give you much better gifts, I think. Yeah, maybe they’ll give you something really good. Expensive things, I don’t know.” The golden eye winked, pulling the foil of the half-decimated candybar a little lower so he could continue his treat.  
  
“I’ll see you, master.”

**Notes for the Chapter:**

> Angry Mango has a 'master's horny bullshit' sensor.


End file.
